Macpaul

Fair point on reading the codes but, oh, diagnosis of these things is a lot more complicated than that........! And the ECU in a Td5 from 1999 is a relatively crude object anyway. To the OP, have you tried a short drive with the fuel cap off (with not much diesel in the tank to avoid spillage)? If the breather pipe is blocked, the pump can struggle against the resulting vacuum in the tank. Also, a poor earth to the ECU can cause problems, so try rigging one temporarily with decent gauge wire direct from the battery to the stud at the bottom of the box under the driver's seat. Also check the fitting of the small black relay in the same box in its socket. This is the main relay and can affect stuff downstream if the connections are corroded, dirty etc. I've been down this road and feel your pain..

"The 2 stroke to add is the good old fashioned mineral oil and not the new high tech synthetic stuff. The old stuff actually mixes with diesel but the new stuff does not." I don't know about mixing (I imagine it would) but mineral is the stuff I have been told is best. Apparently adds lubrication taken out by the removal of sulphur additive (for 'eco' reasons not because it's best).

I use 2 stroke at 1:200 at each fill up, ie 50 litres = 250ml. It was first recommended to me by someone who works on engines at JLR. You can convince yourself it has improved the thing but the first time madam got in after I used it, she said 'what have you done to the engine? It's so much quieter!' She is not a woman known for her mechanical sensitivity.